1. Field of the Invention
The present invention relates generally to a paper binding device, and more particularly to a paper binding device having a unitary device to control the opening or closing of the binding device for keeping papers.
2. Description of the Prior Art
Conventional binding devices for binders have various problems. The binding force of the binding device will decrease with time so that it cannot properly hold the papers in place. The binding rings may hurt or clamp the user's fingers if not properly manipulated. Besides, the binding rings are generally openable at an angle of about 30.degree. and unable to open at a relatively large angle since the binding rings are generally operated by springs that are not allowed much change in angle in the limited space of the binding device. Because of this defect, the user cannot slip a big pile of paper directly onto the binding rings of the binder at one time and has to divide it into several small piles before she/he can put them in place, keeping alert that the binding rings may abruptly close to hurt her/his fingers.